I’ve successfullt entered an ATA Password (called HP DriveLock in my HP laptop) for my Intel 320 SSD using BIOS settings. As a result, my laptop wants me to enter the ATA Password every time I start it up. By design, the password is stored in the SSD and not in the computer’s BIOS.

Suppose I want remove my SSD and connect it to another computer using an eSATA cable or cabinet. If the existing boot disk in this computer have a different ATA password set or no password set at all, I would of course like to enter the password at a later stage (from within Windows) to make the disk accessible.

According to the help system of Rapid Storage Technology Application (RST), I should be able to enter the ATA password by selecting the appropriate disk and then click Unlock.

HP DriveLock, according to the HP User Guides or Maintenance and Service Guides I've read, will present a single password-protected drive for unlocking during the BIOS post. If the boot drive is not password-protected but a data drive is, then it will request the user password for the data drive. I haven't seen any reference as to whether this process treats an eSATA data drive differently. If the password for the data drive isn't entered correctly then the BIOS proceeds to boot without unlocking it.

After the BIOS post, HP DriveLock won't offer to unlock a drive.

It's an interesting reference you've found regarding the Intel RST feature for unlocking a drive. However, I suspect the bit6 HDDLK register is part of the BIOS programming, and can only be modified by modifying the BIOS itself. Someone with knowledge about BIOS programming (Pit, perhaps?) should be able to tell you more.